Practical Asymmetric Approach to Medium-Sized Carbocycles Based on the Combination of Two Ru-Catalyzed Transformations and a Lewis Acid-Induced Cyclization
作者:Fernando López、Luis Castedo、José L. Mascareñas
DOI:10.1021/ol0477125
日期:2005.1.1
[Reaction: see text] Ruthenium-catalyzed coupling of allyl ethyl ether to optically active 1-trimethylsilyl-1-alkyn-3-ols, followed by in situ ketalization and Lewis-acid-induced cyclization, affords enantiomerically pure 1,5-oxygen-bridged eight- and nine-membered carbocycles. Opening of the oxygen bridge under basic or electron transfer conditions provides optically pure medium-sized carbocycles
[反应:参见文本]钌催化的烯丙基乙基醚与光学活性的1-trimethylsilyl-1-alkyn-3-ols偶联,然后进行原位缩酮化和Lewis酸诱导的环化反应,得到对映体纯的1,5-氧桥接的八元和九元摩托车。在碱性或电子转移条件下打开氧桥可提供光学纯的中型碳环化合物,这些产品很难使用其他当前可用的方法来构建。